Electric or electronic timepiece

ABSTRACT

An electric or electronic timepiece having a step motor energized by an electric signal and a second wheel moving intermittently and driven by said rotor. A member is mounted on the rotor, or on an intermediate wheel coupling said rotor and second wheel, for positioning said second wheel at predetermined positions when said electric signal is cut off.

Field of Search....58/23 R, 26.5; 33/34, 35, 85.5

C United States Patent H 1 3 Kurita 4 [451 'Sept. 19, 1972 ELECTRIC OR ELECTRONIC [56] References Cited TIMEPI ECE UNITED STATES PATENTS [72] Inventor: Masahiro Kurita, Suwa, Japan 3 277 644 10/1966 N t I 58/23 731 Assignee: Kabushiki Kaisha Suwa Seikosha, omara e Tokyo Japan Primary Examiner-Richard B. Wilkinson Filedi pt. 1970 Assistant Examiner-Edith C. Simmons Jackmon 1 [211 App]. 70,141 Attorney-Blum, Moscovitz, Friedman & Kaplan [30] Foreign Application Priority Data [57] ABSTRACT An electric or electronic timepiece having a step Sept. 25, l969 Japan ..44/90974 motor energized by an electric signal and a second 52 us. Cl. 58/23 R 58/855 whee Wing inemmemly and drive by Said 511 Int. Cl. nooks/00,0021) 27/00 A member is "mumed the inter [58] mediate wheel coupling said rotor and second wheel,

for positioning said second wheel at predetermined positions when said electric signal is cut off.

6 Claims, 3 Drawing Figures P'ATENTEDSEP 19 m2 SHEET 2 BF 2 1 ELECTRIC OR ELECTRONIC TIMEPIECE BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a preferred embodiment of the movemerit of the electronic timepiece according to the present invention;

FIG. 2 is a plan view of its important parts; and

FIG. 3 shows a driving electric signal wave form of said timepiece.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric or electronic timepiece having a second hand moving intermittently.

In timepieces of the above-mentioned type, it is necessary that the second hand be set closely to the second mark on the dial. The driving signal, supplied by an electronic circuit, has a synchronous action with a regulating position of the second hand, the second hand beingstopped by pulling out the stem and being started by pushing in the stem. j

The object of the'invention is to regulate and actuate the second hand by setting the second hand to the second mark on the dial.

Referring to the'drawings, FIG. 1 shows an electronic timepiece having a battery 1 and a crystal oscillator 2 determining a time standard. The reverse pulse driving signal shown in FIG. 3 is the electric signal produced by crystal oscillator 2 and oscillation circuit 3 as divided by the frequency dividing circuit 4, and is sent to the driving coil 6 connected to the stators and 5 of the step motor. Synchronizing with this signal, a rotor 7 of the step motor, formed from a plurality of permanent magnets having poles circumferentially alternated between North and South, is rotated intermittently at one pole per second. The rotation is transmitted to the second increments wheel 9 through pinion 8 co-axial with the rotor of the step motor. Thus, the second hand is advanced 1 second by the rotation of the rotor by one pole. The second jumper 20, engaging with the teeth of the second wheel, isprovided to regulate fluctuation of the second hand caused by the backlash of the second wheel and rotor pinion. This timepiece is also provided with the reset switch 10, connecting electrically with the frequency dividing circuit 4. The regulating transmitting lever 12, co-axial with the setting lever pin 11, is rotated around the axis of the setting lever pin 11 by pulling out the stem 13, the contact A of the reset switch 10 being alternately linked with and separated from the contact 12A of the regulating transmitting lever 12. The contacts are short-circuited when the stem 13 is pulled out, the regulating transmitting lever and the reset switch being in the position of 12 and 10' in FIG. 2. The contacts are separated when the stem 13 is pushed in, the regulating transmitting lever and the reset switch are in the position of 12 and 10. When the contact of the reset switch is short-circuited, even if the driving signal, sent to the terminals 17 and 18 of the driving coil 6, as shown in FIG. 1, is short-circuited at any time position of one period from T to T of the driving signal, shown in FIG. 3, the frequency dividing circuit 4 will continue to operate as far as the position of T and stop therein and remain at rest while the reset switch is short-circuited. When the short-circuited contact of the reset switch is separated, the frequency dividing circuit will start its operation in a moment, thus releasing the driving signal shown in FIG. 3 from the state of the rest position T causing the driving pulse A to rotate the rotor 7 of the step motor by one pole to advance the second hand a second. The second hand position regulated by said reset switch is limited to any position of odd seconds or even seconds by virtue of necessity of the regulation by synchronizing the reverse pulse of the driving signal with the magnetic poles of the rotor 7.

In FIG. 2, when the stem 13 is pulled out, the regulating transmitting lever 12 will rotate around the setting lever pin 11. After the contact 10A of the reset switch 10 is short-circuited with the contact 12A of the regulating transmitting lever 12, the engaging portion 128 of the regulating transmitting lever 12, which engages the second regulating lever 14, at the initial position, will be released from the engaging portion 14A of the regulating lever 14, so that the second regulating lever 14 will be rotated around the arbor 15 of the regulating lever in a clockwise direction by the resilient regulating lever spring 16, and the rotor regulating portion 14B of the regulating lever will engage in thespace between the projections of cam 19 mounted co-axial with the rotor 7 of the step motor. Said cam has three projections, being half the number of the rotor projections of the step motor said projections being aligned with the magnetic poles of the rotor 7 to that rotor 7 of step motor cam be rotated as soon as said contact of the reset switch is released from the short-circuited state. When thestem is pushed back again, the regulating transmitting lever mounted co-axial with the setting lever 11, as shown in FIG. 2, will rotate in a counterclockwise direction, so that the engaging portion 128 of the regulating transmitting lever 12 will push up the slope 14C of the regulating lever and also rotate the v regulating lever 14 with about arbor 15 in a counterclockwise direction. After rotor regulating portion 148 of the regulating lever is completely free from engagement with cam 19, the engaging portion 128 of the regulating transmitting lever 12 will engage with the engaging portion 14A of the regulating lever 14. The contact 12A of the regulating transmitting lever 12 will be separated from the contact 10A of the reset switch 10 at this portion. The driving signal shown in FIG. 3 will send the driving pulse A from the rest position T to the driving coil 6, so that the rotor 7 of the step motor, placed at the position in which the rotor can be rotated by the driving pulse A, will be rotated.

The provision of cam 19, the member to be regulated, mounted co-axial with the rotor 7 of the step motor provides numerous advantages. It is possible not only to decrease the number of a cam teeth, but to produce the small and light cam. The second hand can be regulated by setting to the second mark on the dial, while the position of the magnetic pole of the rotor can be regulated exactly. Further, the next incremental movement of the magnetic pole can be easily achieved upon the removal of regulation. The simple structure of the rotor regulating portion of the regulating lever is made possible, because the teeth of the cam to be re gulated are few and pitches are large.

If the object of the invention is performed by regulating the second wheel directly, it is necessary to provide a member to be regulated having 30 teeth mounted on the second wheel having 60 teeth, so that a timepiece pitch cannot be provided unless the outer diameter is enlarged, thereby making it difficult to form the regulating portion of the regulating lever in a small size, thereby reducing the second regulating accuracy.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments being practiced or carried out in various ways.

What is claimed is:

1. An electric or electronic timepiece comprising a step motor having a rotor; means for producing an electric driving signal connected to said step motor for incrementally advancing said rotor; a second wheel operatively coupled to said rotor for incremental rotation in response thereto; cam means mounted on said rotor for rotation therewith; and means displaceable into and out of engagement with said cam means coordinated with the cutting off and restarting of said electric signal respectively for rotatably positioning said rotor, and therefore said second wheel, at predetermined positions when said electric signal is cut off.

2. An electric or electronic timepiece as recited in claim 1, wherein said rotor is formed with n poles, said cam means being formed with n/2 radially extending projection for receiving said displaceable means therebetween, said projection being aligned relative to said poles for the positioning of said rotor at one of n/2 positions when said electric signal is cut off.

3. An electric or electronic timepiece as recited in claim 1, including means projecting externally of said timepiece and operatively coupled to said electric signal producing means and said displaceable means for coordinately cutting off and restarting said electric signal and displacing said displaceable means.

4. An electric or electronic timepiece comprising a step motor having a rotor; means for producing a driving electric signal for incrementally rotating said rotor; an intermediate wheel operatively coupled to said rotor for rotation therewith; a second wheel operatively coupled to said intermediate wheel for incremental rotation in response to the rotation of said rotor; cam means mounted on said intermediate wheel for rotation therewith; and means displaceable into and out of engagement with said cam means for positioning said intermediate wheel, and therefore said second wheel, at predetermined positions when said elector signal is cut off.

5. An electric or electronic timepiece as recited in claim 4, wherein said rotor is formed with n poles, said cam means being formed with n/2 projections for receiving said displaceable means therebetween to position said cam means at n/2 predetermined positions.

6. An electric or electronic timepiece as recited in claim 4, including means projecting externally of said timepiece and operatively coupled to said electric signal producing means and said displaceable means for coordinately cutting off and restarting said electric signal and displacing said displaceable means. 

1. An electric or electronic timepiece comprising a step motor having a rotor; means for producing an electric driving signal connected to said step motor for incrementally advancing said rotor; a second wheel operatively coupled to said rotor for incremental rotation in response thereto; cam means mounted on said rotor for rotation therewith; and means displaceable into and out of engagement with said cam means coordinated with the cutting off and restarting of said electric signal respectively for rotatably positioning said rotor, and therefore said second wheel, at predetermined positions when said electric signal is cut off.
 2. An electric or electronic timepiece as recited in claim 1, wherein said rotor is formed with n poles, said cam means being formed with n/2 radially extending projection for receiving said displaceable means therebetween, said projection being aligned relative to said poles for the positioning of said rotor at one of n/2 positions when said electric signal is cut off.
 3. An electric or electronic timepiece as recited in claim 1, including means projecting externally of said timepiece and operatively coupled to said electric signal producing means and said displaceable means for coordinately cutting off and restarting said electric signal and displacing said displaceable means.
 4. An electric or electronic timepiece comprising a step motor having a rotor; means for producing a driving electric signal for incrementally rotating said rotor; an intermediate wheel operatively coupled to said rotor for rotation therewith; a second wheel operatively coupled to said intermediate wheel for incremental rotation in response to the rotation of said rotor; cam means mounted on said intermediate wheel for rotation therewith; and means displaceable into and out of engagement with said cam means for positioning said intermediate wheel, and therefore said second wheel, at predetermined positions when said elector signal is cut off.
 5. An electric or electronic timepiece as recited in claim 4, wherein said rotor is formed with n poles, said cam means being formed with n/2 projections for receiving said displaceable means therebetween to position said cam means at n/2 predetermined positions.
 6. An electric or electronic timepiece as recited in claim 4, including means projecting externally of said timepiece and operatively coupled to said electric signal producing means and said displaceable means for coordinately cutting off and restarting said electric signal and displacing said displaceable means. 